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Chou S, Alain S, Cervera C, Chemaly RF, Kotton CN, Lundgren J, Papanicolaou GA, Pereira MR, Wu JJ, Murray RA, Buss NE, Fournier M. Drug Resistance Assessed in a Phase 3 Clinical Trial of Maribavir Therapy for Refractory or Resistant Cytomegalovirus Infection in Transplant Recipients. J Infect Dis 2024; 229:413-421. [PMID: 37506264 PMCID: PMC10873177 DOI: 10.1093/infdis/jiad293] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/18/2023] [Accepted: 07/27/2023] [Indexed: 07/30/2023] Open
Abstract
BACKGROUND This drug resistance analysis of a randomized trial includes 234 patients receiving maribavir and 116 receiving investigator-assigned standard therapy (IAT), where 56% and 24%, respectively, cleared cytomegalovirus DNA at week 8 (treatment responders). METHODS Baseline and posttreatment plasma samples were tested for mutations conferring drug resistance in viral genes UL97, UL54, and UL27. RESULTS At baseline, genotypic testing revealed resistance to ganciclovir, foscarnet, or cidofovir in 56% of patients receiving maribavir and 68% receiving IAT, including 9 newly phenotyped mutations. Among them, 63% (maribavir) and 21% (IAT) were treatment responders. Detected baseline maribavir resistance mutations were UL27 L193F (n = 1) and UL97 F342Y (n = 3). Posttreatment, emergent maribavir resistance mutations were detected in 60 (26%) of those randomized to maribavir, including 49 (48%) of 103 nonresponders and 25 (86%) of the 29 nonresponders where viral DNA initially cleared then rebounded while on maribavir. The most common maribavir resistance mutations were UL97 T409M (n = 34), H411Y (n = 26), and C480F (n = 21), first detected 26 to 130 (median 56) days after starting maribavir. CONCLUSIONS Baseline maribavir resistance was rare. Drug resistance to standard cytomegalovirus antivirals did not preclude treatment response to maribavir. Rebound in plasma cytomegalovirus DNA while on maribavir strongly suggests emerging drug resistance. CLINICAL TRIALS REGISTRATION NCT02931539.
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Affiliation(s)
- Sunwen Chou
- Division of Infectious Diseases, Oregon Health and Science University, Portland, Oregon, USA
- Research and Development Service, Veterans Affairs Portland Health Care System, Portland, Oregon, USA
| | - Sophie Alain
- Department of Virology and National Reference Center for Herpesviruses, Limoges University Hospital, UMR Inserm 1092, University of Limoges, Limoges, France
| | - Carlos Cervera
- Division of Infectious Diseases, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Roy F Chemaly
- Department of Infectious Diseases, Infection Control, and Employee Health, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Camille N Kotton
- Transplant and Immunocompromised Host Infectious Diseases, Infectious Diseases Division, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Jens Lundgren
- Centre for Health and Infectious Disease Research, Department of Infectious Diseases, Rigshospitalitet, University of Copenhagen, Copenhagen, Denmark
| | - Genovefa A Papanicolaou
- Infectious Disease Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
- Department of Medicine, Weill Cornell Medicine, New York, New York, USA
| | - Marcus R Pereira
- Department of Medicine, Columbia University Medical Center, New York, New York, USA
| | - Jingyang J Wu
- Takeda Development Center Americas, Inc., Lexington, Massachusetts, USA
| | - Rose Ann Murray
- Takeda Development Center Americas, Inc., Lexington, Massachusetts, USA
| | - Neil E Buss
- Medical Expressions, Büren, Solothurn, Switzerland
| | - Martha Fournier
- Takeda Development Center Americas, Inc., Lexington, Massachusetts, USA
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Chou S, Watanabe J. Ganciclovir and maribavir cross-resistance revisited: Relative drug susceptibilities of canonical cytomegalovirus mutants. Antiviral Res 2024; 222:105792. [PMID: 38163624 PMCID: PMC10922325 DOI: 10.1016/j.antiviral.2023.105792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 12/26/2023] [Accepted: 12/27/2023] [Indexed: 01/03/2024]
Abstract
Therapeutic use of maribavir for human cytomegalovirus infection has renewed attention to the extent of cross-resistance with ganciclovir as the existing standard therapy. Each drug selects in vivo for a characteristic set of resistance mutations in the viral UL97 kinase gene. To improve the calibration of relative susceptibilities to each drug, genetic variants at relevant UL97 codons were extensively phenotyped using the same baseline viral clone, cell culture conditions and growth readout. Ganciclovir-selected mutations at codons 460, 520, 592, 594, 595 and 603 conferred 2.8-fold (C603Y) to 12-fold (M460I) increases in ganciclovir 50% inhibitory concentrations (EC50) over wild type baseline, while conferring maribavir EC50 fold changes ranging from 0.21-fold (M460I) to 1.9-fold (A594V). Maribavir-selected mutations at codons 409, 411 and 480 conferred maribavir EC50 fold changes ranging from 17 (H411Y) to 210 (C480F), while conferring ganciclovir EC50 fold changes ranging from 0.7 (H411Y) to 2.3 (C480F). The P-loop substitution F342Y, selected by either drug, is confirmed to confer 4.7-fold and 6-fold increases in maribavir and ganciclovir EC50s respectively, and suggests this part of the ATP-binding domain of UL97 to be involved in moderate resistance to both drugs. The maribavir hypersensitivity of M460I and M460V may be advantageous.
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Affiliation(s)
- Sunwen Chou
- Department of Veterans Affairs Medical Center, Portland, OR, USA; Division of Infectious Diseases, Oregon Health and Science University, USA.
| | - Justin Watanabe
- Department of Veterans Affairs Medical Center, Portland, OR, USA
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Streck NT, Espy MJ, Ferber MJ, Klee EW, Razonable RR, Gonzalez D, Sayada C, Heaton PR, Chou S, Binnicker MJ. Use of next-generation sequencing to detect mutations associated with antiviral drug resistance in cytomegalovirus. J Clin Microbiol 2023; 61:e0042923. [PMID: 37750719 PMCID: PMC10595055 DOI: 10.1128/jcm.00429-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 07/25/2023] [Indexed: 09/27/2023] Open
Abstract
Cytomegalovirus (CMV) is a significant cause of morbidity and mortality among immunocompromised hosts, including transplant recipients. Antiviral prophylaxis or treatment is used to reduce the incidence of CMV disease in this patient population; however, there is concern about increasing antiviral resistance. Detection of antiviral resistance in CMV was traditionally accomplished using Sanger sequencing of UL54 and UL97 genes, in which specific mutations may result in reduced antiviral activity. In this study, a novel next-generation sequencing (NGS) method was developed and validated to detect mutations in UL54/UL97 associated with antiviral resistance. Plasma samples (n = 27) submitted for antiviral resistance testing by Sanger sequencing were also analyzed using the NGS method. When compared to Sanger sequencing, the NGS assay demonstrated 100% (27/27) overall agreement for determining antiviral resistance/susceptibility and 88% (22/25) agreement at the level of resistance-associated mutations. The limit of detection of the NGS method was determined to be 500 IU/mL, and the lower threshold for detecting mutations associated with resistance was established at 15%. The NGS assay represents a novel laboratory tool that assists healthcare providers in treating patients who are infected with CMV harboring resistance-associated mutations and who may benefit from tailored antiviral therapy.
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Affiliation(s)
- Nicholas T. Streck
- Division of Clinical Microbiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Mark J. Espy
- Division of Clinical Microbiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Matthew J. Ferber
- Division of Laboratory Genetics and Genomics, Mayo Clinic, Rochester, Minnesota, USA
| | - Eric W. Klee
- Division of Biomedical Statistics and Informatics, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Raymund R. Razonable
- Division of Public Health, Infectious Diseases and Occupational Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | | | | | - Phillip R. Heaton
- Health Partners Medical Laboratory and Pathology Services, Bloomington, Minnesota, USA
| | - Sunwen Chou
- Research Service, Department of Veterans Affairs Medical Center, Portland, Oregon, USA
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Chou S, Kleiboeker S. Relative frequency of cytomegalovirus UL56 gene mutations detected in genotypic letermovir resistance testing. Antiviral Res 2022; 207:105422. [PMID: 36170912 PMCID: PMC9759347 DOI: 10.1016/j.antiviral.2022.105422] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/13/2022] [Accepted: 09/18/2022] [Indexed: 11/24/2022]
Abstract
Genotypic testing for letermovir (LMV) resistance was performed by Sanger sequencing of cytomegalovirus terminase gene UL56 (codons 202-412) in 1165 diagnostic specimens, disclosing 36 sequence variants among 173 (14.8%) of the specimens, including one or more LMV resistance mutations in 134 specimens. Codon 325 mutations (C325Y/F/W/R) were the most common (108 specimens), followed by those at codon 369 (R369 S/G/T/K, 13 specimens) and V236M (11 specimens). Mutations V231L, N232Y, Q234R, L257F and V363I were detected in 1-3 specimens each. Combinations of codon 325 mutation and those at codons 236 or 369 were found in 6 specimens. Eleven novel sequence variants were phenotyped, validating Q234R, V363I and R369K as conferring 2- to 5-fold increased LMV 50% inhibitory concentrations (EC50). These findings indicate that UL56 codon 325 mutations conferring >3000-fold LMV EC50 are detected much more frequently in clinical practice than those conferring lower grade resistance, and suggest that a single step mutation to absolute LMV resistance is an ongoing concern in its therapeutic use.
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Affiliation(s)
- Sunwen Chou
- Department of Veterans Affairs Medical Center, Portland, OR, USA; Division of Infectious Diseases, Oregon Health and Science University, USA.
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Schütz M, Müller R, Socher E, Wangen C, Full F, Wyler E, Wong D, Scherer M, Stamminger T, Chou S, Rawlinson WD, Hamilton ST, Sticht H, Marschall M. Highly Conserved Interaction Profiles between Clinically Relevant Mutants of the Cytomegalovirus CDK-like Kinase pUL97 and Human Cyclins: Functional Significance of Cyclin H. Int J Mol Sci 2022; 23:ijms231911814. [PMID: 36233116 PMCID: PMC9569496 DOI: 10.3390/ijms231911814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/28/2022] [Accepted: 09/29/2022] [Indexed: 12/03/2022] Open
Abstract
The complex host interaction network of human cytomegalovirus (HCMV) involves the regulatory protein kinase pUL97, which represents a viral cyclin-dependent kinase (CDK) ortholog. pUL97 interacts with the three human cyclin types T1, H, and B1, whereby the binding region of cyclin T1 and the pUL97 oligomerization region were both assigned to amino acids 231-280. We further addressed the question of whether HCMVs harboring mutations in ORF-UL97, i.e., short deletions or resistance-conferring point mutations, are affected in the interaction with human cyclins and viral replication. To this end, clinically relevant UL97 drug-resistance-conferring mutants were analyzed by whole-genome sequencing and used for genetic marker transfer experiments. The recombinant HCMVs indicated conservation of pUL97–cyclin interaction, since all viral UL97 point mutants continued to interact with the analyzed cyclin types and exerted wild-type-like replication fitness. In comparison, recombinant HCMVs UL97 Δ231-280 and also the smaller deletion Δ236-275, but not Δ241-270, lost interaction with cyclins T1 and H, showed impaired replication efficiency, and also exhibited reduced kinase activity. Moreover, a cellular knock-out of cyclins B1 or T1 did not alter HCMV replication phenotypes or pUL97 kinase activity, possibly indicating alternative, compensatory pUL97–cyclin interactions. In contrast, however, cyclin H knock-out, similar to virus deletion mutants in the pUL97–cyclin H binding region, exhibited strong defective phenotypes of HCMV replication, as supported by reduced pUL97 kinase activity in a cyclin H-dependent coexpression setting. Thus, cyclin H proved to be a very relevant determinant of pUL97 kinase activity and viral replication efficiency. As a conclusion, the results provide evidence for the functional importance of pUL97–cyclin interaction. High selective pressure on the formation of pUL97–cyclin complexes was identified by the use of clinically relevant mutants.
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Affiliation(s)
- Martin Schütz
- Institute for Clinical and Molecular Virology, FAU Erlangen-Nürnberg, 91054 Erlangen, Germany
- Correspondence: (M.S.); (M.M.); Tel.: +49-9131-8526089 (M.M.)
| | - Regina Müller
- Institute for Clinical and Molecular Virology, FAU Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Eileen Socher
- Institute for Clinical and Molecular Virology, FAU Erlangen-Nürnberg, 91054 Erlangen, Germany
- Division of Bioinformatics, Institute of Biochemistry, FAU Erlangen-Nürnberg, 91054 Erlangen, Germany
- Functional and Clinical Anatomy, Institute of Anatomy, FAU Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Christina Wangen
- Institute for Clinical and Molecular Virology, FAU Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Florian Full
- Institute of Virology, University Medical Center, Faculty of Medicine, Albert-Ludwig-University Freiburg, 79110 Freiburg, Germany
| | - Emanuel Wyler
- Max-Delbrück-Center for Molecular Medicine (MDC), 13125 Berlin, Germany
| | - Diana Wong
- Serology and Virology Division, NSW Health Pathology, Prince of Wales Hospital, Sydney 2031, Australia
- School of Medical Sciences, University of New South Wales, Sydney 2052, Australia
| | - Myriam Scherer
- Institute for Virology, Ulm University Medical Center, 89070 Ulm, Germany
| | - Thomas Stamminger
- Institute for Virology, Ulm University Medical Center, 89070 Ulm, Germany
| | - Sunwen Chou
- Division of Infectious Diseases, Oregon Health and Science University, Portland, OR 97239, USA
- Department of Veterans Affairs Medical Center, Portland, OR 97239, USA
| | - William D. Rawlinson
- Serology and Virology Division, NSW Health Pathology, Prince of Wales Hospital, Sydney 2031, Australia
- School of Medical Sciences, University of New South Wales, Sydney 2052, Australia
- School of Women’s and Children’s Health, University of New South Wales, Sydney 2031, Australia
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2033, Australia
| | - Stuart T. Hamilton
- Serology and Virology Division, NSW Health Pathology, Prince of Wales Hospital, Sydney 2031, Australia
- School of Women’s and Children’s Health, University of New South Wales, Sydney 2031, Australia
| | - Heinrich Sticht
- Division of Bioinformatics, Institute of Biochemistry, FAU Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Manfred Marschall
- Institute for Clinical and Molecular Virology, FAU Erlangen-Nürnberg, 91054 Erlangen, Germany
- Correspondence: (M.S.); (M.M.); Tel.: +49-9131-8526089 (M.M.)
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Umano A, Fang K, Qu Z, Scaglione JB, Altinok S, Treadway CJ, Wick ET, Paulakonis E, Karunanayake C, Chou S, Bardakjian TM, Gonzalez-Alegre P, Page RC, Schisler JC, Brown NG, Yan D, Scaglione KM. The molecular basis of spinocerebellar ataxia type 48 caused by a de novo mutation in the ubiquitin ligase CHIP. J Biol Chem 2022; 298:101899. [PMID: 35398354 PMCID: PMC9097460 DOI: 10.1016/j.jbc.2022.101899] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/24/2022] [Accepted: 03/28/2022] [Indexed: 11/25/2022] Open
Abstract
The spinocerebellar ataxias (SCAs) are a class of incurable diseases characterized by degeneration of the cerebellum that results in movement disorder. Recently, a new heritable form of SCA, spinocerebellar ataxia type 48 (SCA48), was attributed to dominant mutations in STIP1 homology and U box-containing 1 (STUB1); however, little is known about how these mutations cause SCA48. STUB1 encodes for the protein C terminus of Hsc70 interacting protein (CHIP), an E3 ubiquitin ligase. CHIP is known to regulate proteostasis by recruiting chaperones via a N-terminal tetratricopeptide repeat domain and recruiting E2 ubiquitin-conjugating enzymes via a C-terminal U-box domain. These interactions allow CHIP to mediate the ubiquitination of chaperone-bound, misfolded proteins to promote their degradation via the proteasome. Here we have identified a novel, de novo mutation in STUB1 in a patient with SCA48 encoding for an A52G point mutation in the tetratricopeptide repeat domain of CHIP. Utilizing an array of biophysical, biochemical, and cellular assays, we demonstrate that the CHIPA52G point mutant retains E3-ligase activity but has decreased affinity for chaperones. We further show that this mutant decreases cellular fitness in response to certain cellular stressors and induces neurodegeneration in a transgenic Caenorhabditis elegans model of SCA48. Together, our data identify the A52G mutant as a cause of SCA48 and provide molecular insight into how mutations in STUB1 cause SCA48.
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Affiliation(s)
- A Umano
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, USA
| | - K Fang
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, USA
| | - Z Qu
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, USA
| | - J B Scaglione
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, USA
| | - S Altinok
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - C J Treadway
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA; Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - E T Wick
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA; Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - E Paulakonis
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA; Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - C Karunanayake
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio, USA
| | - S Chou
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, USA; Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - T M Bardakjian
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - P Gonzalez-Alegre
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - R C Page
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio, USA
| | - J C Schisler
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - N G Brown
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA; Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - D Yan
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, USA
| | - K M Scaglione
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, USA; Department of Neurology, Duke University, Durham, North Carolina, USA; Duke Center for Neurodegeneration and Neurotherapeutics, Duke University, Durham, North Carolina, USA.
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Chou S. Opposite effects of cytomegalovirus UL54 exonuclease domain mutations on acyclovir and cidofovir susceptibility. Antiviral Res 2021; 195:105181. [PMID: 34560144 DOI: 10.1016/j.antiviral.2021.105181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 09/17/2021] [Accepted: 09/20/2021] [Indexed: 11/18/2022]
Abstract
Acyclovir has weak activity against human cytomegalovirus (CMV). Despite some efficacy as prophylaxis, more potent anti-CMV drugs are preferred. Acyclovir resistance of CMV has been little studied. The viral UL97 kinase phosphorylates acyclovir, and cross-resistance of ganciclovir-resistant mutants is documented. However, UL54 exonuclease domain mutants may confer ganciclovir and cidofovir resistance by a mechanism that does not apply to acyclovir as an obligate chain terminator. To test for differential susceptibilities, 11 exonuclease domain mutants were tested for their 50% inhibitory concentrations (EC50s) of acyclovir in comparison with cidofovir. The 5 mutants with the highest cidofovir EC50s (>10-fold increased over wild type) all had acyclovir EC50s less than 20% of wild type. The relatively common N408K mutant had an acyclovir EC50 of 6 μM, comparable to that reported for wild type varicella-zoster virus. Several foscarnet-resistant UL54 mutants outside the exonuclease domains, some with low-grade ganciclovir/cidofovir cross-resistance, showed various degrees of acyclovir resistance. Based on these in vitro data, acyclovir may become a therapeutic option when a highly cidofovir-resistant exonuclease mutation is present without a simultaneous mutation in UL97.
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Affiliation(s)
- Sunwen Chou
- Division of Infectious Diseases, Oregon Health and Science University and Department of Veterans Affairs Medical Center, Portland, OR, USA
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Chou S, Watters M, Sinha R, Kleiboeker S. Ganciclovir and maribavir susceptibility phenotypes of cytomegalovirus UL97 ATP binding region mutations detected by expanded genotypic testing. Antiviral Res 2021; 193:105139. [PMID: 34273445 DOI: 10.1016/j.antiviral.2021.105139] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 07/10/2021] [Accepted: 07/12/2021] [Indexed: 10/20/2022]
Abstract
Because ganciclovir resistance mutations in the cytomegalovirus UL97 gene most commonly occur at codons 460, 520 and 590-607, diagnostic genotyping for drug resistance has often omitted the analysis of codons below 440. However, the UL97 kinase inhibitor maribavir selects for distinctive resistance mutations at codons 409 and 411, and ganciclovir/maribavir resistance mutations have also been described in the ATP binding region starting at codon 335. Expanded genotypic testing of UL97 codons 335-440 in 1535 clinical specimens disclosed 10 uncharacterized sequence variants that were phenotyped for ganciclovir and maribavir susceptibility. Notable findings included low-grade ganciclovir resistance conferred by amino acid substitutions K359N and E362D, decreased maribavir susceptibility of L348V, and maribavir hypersensitivity of V345I and E362D. Recently published substitutions F342Y and K359E/Q were also confirmed. The data indicate that mutations in the UL97 ATP binding region may arise in clinical specimens to affect the interpretation of ganciclovir and maribavir resistance. This region should now be included in the standard diagnostic genotyping of UL97, especially with the introduction of maribavir into therapeutic use.
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Affiliation(s)
- Sunwen Chou
- Division of Infectious Diseases, Oregon Health and Science University, Department of Veterans Affairs Medical Center, Portland, OR, USA.
| | - Matthew Watters
- Viracor Euroflns Clinical Diagnostics, Lee's Summit, MO, USA
| | - Rohita Sinha
- Viracor Euroflns Clinical Diagnostics, Lee's Summit, MO, USA
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Truong K, Venning V, Wain T, Chou S, Fernandez-Peñas P. Successful treatment of highly refractory necrobiotic xanthogranuloma with peginterferon alfa-2a. Clin Exp Dermatol 2021; 46:731-733. [PMID: 33222242 DOI: 10.1111/ced.14523] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/19/2020] [Indexed: 11/30/2022]
Affiliation(s)
- K Truong
- Departments of, Department of, Dermatology, Westmead Hospital, Sydney, NSW, Australia
| | - V Venning
- Departments of, Department of, Dermatology, Westmead Hospital, Sydney, NSW, Australia
| | - T Wain
- Departments of, Department of, Dermatology, Westmead Hospital, Sydney, NSW, Australia
| | - S Chou
- Department of, Tissue Pathology and Diagnostic Oncology, Westmead Hospital, Sydney, NSW, Australia
| | - P Fernandez-Peñas
- Departments of, Department of, Dermatology, Westmead Hospital, Sydney, NSW, Australia
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Douglas CM, Barnard R, Holder D, Leavitt R, Levitan D, Maguire M, Nickle D, Teal V, Wan H, van Alewijk DCJG, van Doorn LJ, Chou S, Strizki J. Letermovir Resistance Analysis in a Clinical Trial of Cytomegalovirus Prophylaxis for Hematopoietic Stem Cell Transplant Recipients. J Infect Dis 2021; 221:1117-1126. [PMID: 31781762 DOI: 10.1093/infdis/jiz577] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 11/14/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Letermovir (LET), a cytomegalovirus (CMV) deoxyribonucleic acid (DNA) terminase inhibitor, was recently approved for prophylaxis of CMV infection in adult CMV-seropositive recipients of allogeneic hematopoietic stem cell transplantation. Cytomegalovirus genotyping was performed to identify LET-resistance-associated variants (RAVs) among subjects in a Phase 3 trial. METHODS The CMV UL56 and UL89 genes, encoding subunits of CMV DNA terminase, were sequenced from plasma collected from subjects with clinically significant CMV infection (CS-CMVi). Novel variants were evaluated by recombinant phenotyping to assess their potential to confer resistance to LET. RESULTS Genotyping was successful for 50 of 79 LET subjects with CS-CMVi. Resistance-associated variants (encoding pUL56 V236M and C325W) were detected independently in subjects 1 and 3 who experienced CS-CMVi while receiving LET prophylaxis, and 2 other variants (encoding pUL56 E237G and R369T) were detected >3 weeks after subjects 2 and 3, respectively, had discontinued LET prophylaxis and received preemptive therapy with ganciclovir. CONCLUSIONS The detected incidence of CMV resistance among subjects who received LET as prophylaxis in this Phase 3 trial was low. The LET RAVs that were detected mapped to the CMV UL56 gene at positions associated with reduced susceptibility to LET based on resistance selections in cell culture.
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Affiliation(s)
- Cameron M Douglas
- Infectious Disease Research, Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - Richard Barnard
- Infectious Disease Research, Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - Daniel Holder
- Biostatistics and Research Decision Sciences, Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - Randi Leavitt
- Clinical Research, Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - Diane Levitan
- Translational Molecular Biomarkers, Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - Maureen Maguire
- Translational Molecular Biomarkers, Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - David Nickle
- Pharmacogenomics and Genetics, Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - Valerie Teal
- Biostatistics and Research Decision Sciences, Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - Hong Wan
- Biostatistics and Research Decision Sciences, Merck & Co., Inc., Kenilworth, New Jersey, USA
| | | | | | - Sunwen Chou
- Department of Veterans Affairs Medical Center, Oregon Health and Science University, Portland, Oregon, USA
| | - Julie Strizki
- Infectious Disease Research, Merck & Co., Inc., Kenilworth, New Jersey, USA
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11
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Zhao ZM, Yin ZZ, Pan LC, Liu Q, Chou S, Liu R. [Multimodality navigation for liver resection of complicated alveolar echinococcosis]. Zhonghua Yi Xue Za Zhi 2020; 100:3525-3528. [PMID: 33256296 DOI: 10.3760/cma.j.cn112137-20200327-00957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To investigate the clinical application of multimodality navigation for liver resection in the treatment of complicated alveolar echinococcosis (AE). Methods: From October 2019 to February 2020, the clinical data and perioperative results of patients with AE treated by surgery in our department were retrospectively studied. Hepatic parenchyma disconnection plane and liver resection were navigated and performed with three-dimensional reconstruction and HITACHI real-time multi-image fusion interventional navigation system (RVS). Results: All of six patients were successful performed radical liver resection without mortality. The operation time was (301±106)min and the median blood loss was 200 ml. Two patients needed blood transfusion intraoperative (33.33%). The postoperative hospital stay was (10.8±2.8) day, and the cost of hospitalization was (82 584±995.61) yuan. Clavien-Dindo grade Ⅲ complication occurred in one patient. Conclusions: Multimodality navigation might provide precise intraoperative navigation of the surgical plane and effectively assist liver resection for the treatment of complicated AE.
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Affiliation(s)
- Z M Zhao
- The Second Department of Hepatopancreatobiliary Surgery, the First Medical Center, Chinese People's Liberation Army General Hospital, Haidian district, Beijing, 100853, China
| | - Z Z Yin
- The Second Department of Hepatopancreatobiliary Surgery, the First Medical Center, Chinese People's Liberation Army General Hospital, Haidian district, Beijing, 100853, China
| | - L C Pan
- The Second Department of Hepatopancreatobiliary Surgery, the First Medical Center, Chinese People's Liberation Army General Hospital, Haidian district, Beijing, 100853, China
| | - Q Liu
- The Second Department of Hepatopancreatobiliary Surgery, the First Medical Center, Chinese People's Liberation Army General Hospital, Haidian district, Beijing, 100853, China
| | - S Chou
- The Second Department of Hepatopancreatobiliary Surgery, the First Medical Center, Chinese People's Liberation Army General Hospital, Haidian district, Beijing, 100853, China
| | - R Liu
- The Second Department of Hepatopancreatobiliary Surgery, the First Medical Center, Chinese People's Liberation Army General Hospital, Haidian district, Beijing, 100853, China
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12
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Chou S, Song K, Wu J, Bo T, Crumpacker C. Drug resistance mutations and associated phenotypes detected in clinical trials of maribavir for treatment of cytomegalovirus infection. J Infect Dis 2020; 226:576-584. [PMID: 32726419 PMCID: PMC9441206 DOI: 10.1093/infdis/jiaa462] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 07/24/2020] [Indexed: 01/26/2023] Open
Abstract
Background In separate phase 2 trials, 120 patients received maribavir for cytomegalovirus (CMV) infection failing conventional therapy (trial 202) and 119 received maribavir for asymptomatic infection (trial 203). Overall, 172 cleared their CMV infection (CMV DNA <200 copies/mL) within 6 weeks. Methods Baseline and posttreatment plasma samples were tested for mutations in viral genes UL97, UL54, and/or UL27. Selected viral mutants were phenotyped for drug susceptibility. Results Baseline samples revealed UL54 mutations newly phenotyped as conferring resistance to standard DNA polymerase inhibitor(s), including K493N, P497S, K513T, L565V, V823A, A987V, and E989D. Of 29 patients (including 25 from trial 202) who cleared but later experienced recurrent CMV infection while on maribavir, 23 had available UL97 genotyping data; 17 had known resistance mutations (T409M or H411Y) and 5 additional had UL97 C480F alone. The newly phenotyped mutation C480F conferred high-grade maribavir resistance and low-grade ganciclovir resistance. Among 25 who did not respond to >14 days of therapy, 9 showed T409M or H411Y and 4 others showed C480F alone. Conclusions After maribavir therapy (400–1200 mg twice daily), UL97 mutations T409M, H411Y, or C480F emerge to confer maribavir resistance in patients with recurrent CMV infection while on therapy or no response to therapy. Clinical Trials Registration NCT01611974 and EudraCT 2010-024247-32.
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Affiliation(s)
- Sunwen Chou
- Oregon Health & Science University and VA Health Care System, Portland OR
| | - Kening Song
- Shire Human Genetic Therapies Inc., Lexington MA, a Takeda Company
| | - Jingyang Wu
- Shire Human Genetic Therapies Inc., Lexington MA, a Takeda Company
| | - Tien Bo
- Shire Human Genetic Therapies Inc., Lexington MA, a Takeda Company
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13
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Chemaly RF, Chou S, Einsele H, Griffiths P, Avery R, Razonable RR, Mullane KM, Kotton C, Lundgren J, Komatsu TE, Lischka P, Josephson F, Douglas CM, Umeh O, Miller V, Ljungman P. Definitions of Resistant and Refractory Cytomegalovirus Infection and Disease in Transplant Recipients for Use in Clinical Trials. Clin Infect Dis 2020; 68:1420-1426. [PMID: 30137245 DOI: 10.1093/cid/ciy696] [Citation(s) in RCA: 119] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 08/17/2018] [Indexed: 12/15/2022] Open
Abstract
Despite advances in preventive strategies, cytomegalovirus (CMV) infection remains a major complication in solid organ and hematopoietic cell transplant recipients. CMV infection may fail to respond to commercially available antiviral therapies, with or without demonstrating genotypic mutation(s) known to be associated with resistance to these therapies. This lack of response has been termed "resistant/refractory CMV" and is a key focus of clinical trials of some investigational antiviral agents. To provide consistent criteria for future clinical trials and outcomes research, the CMV Resistance Working Group of the CMV Drug Development Forum (consisting of scientists, clinicians, regulatory officials, and industry representatives from the United States, Canada, and Europe) has undertaken establishing standardized consensus definitions of "resistant" and "refractory" CMV. These definitions have emerged from the Working Group's review of the available virologic and clinical literature and will be subject to reassessment and modification based on results of future studies.
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Affiliation(s)
- Roy F Chemaly
- Department of Infectious Diseases, Infection Control, and Employee Health, University of Texas MD Anderson Cancer Center, Houston
| | - Sunwen Chou
- Division of Infectious Diseases, Oregon Health and Science University, and Research and Development Service, Veterans Affairs Portland Health Care System
| | - Hermann Einsele
- Department of Internal Medicine II, University Hospital Wuerzburg, Germany
| | - Paul Griffiths
- Institute for Immunity and Transplantation, University College London Medical School, United Kingdom
| | - Robin Avery
- Division of Infectious Diseases, Department of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Raymund R Razonable
- Division of Infectious Diseases, Department of Medicine, William J. von Liebig Center for Transplantation and Clinical Regeneration, Mayo Clinic, Rochester, Minnesota
| | - Kathleen M Mullane
- Section of Infectious Diseases and Global Health, Department of Medicine, University of Chicago, Illinois
| | - Camille Kotton
- Infectious Diseases Division, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Jens Lundgren
- Centre for Health and Infectious Disease Research, Department of Infectious Diseases, Rigshospitalet, University of Copenhagen, Denmark
| | - Takashi E Komatsu
- Division of Antiviral Products, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland
| | - Peter Lischka
- AiCuris Anti-infective Cures GmbH, Wuppertal, Germany
| | | | | | - Obi Umeh
- Shire Global Clinical Development (Immunology Therapeutic Area), Lexington, Massachusetts
| | - Veronica Miller
- Forum for Collaborative Research, University of California, Berkeley
| | - Per Ljungman
- Department of Cellular Therapy and Allogeneic Stem Cell Transplantation, Karolinska University Hospital.,Division of Hematology, Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden
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14
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Chou S, Chang ZY, Zhao GD, Song DD, Zhang X, Hu MG, Liu R. [Robotic hilar cholangiocarcinoma radical resection compared with laparotomy in prognosis]. Zhonghua Wai Ke Za Zhi 2020; 58:230-234. [PMID: 32187928 DOI: 10.3760/cma.j.issn.0529-5815.2020.03.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To compare the long term and short term outcomes between robotic and open surgery for hilar cholangiocarcinoma radical resection. Methods: This is a single-center and retrospective case-control study. Patients underwent hilar cholangiocarcinoma radical resection between January 2016 and December 2016 at Department of Hepatobiliary Surgery of the General Hospital of the Chinese People's Liberation Army were included. Safety, effectiveness and long-term prognosis of tumors were evaluated. Patients were divided into robotic hilar cholangiocarcinoma radical surgery group (robotic group, n=16) and open hepatic hilar cholangiocarcinoma radical surgery group (open group, n=31) . All cases were confirmed by pathology histological. Age, gender, histology, resection margin status, extent of surgical resection, disease-free survival (DFS) , and overall survival (OS) were retrospectively collected and analyzed.In the follow-up cohort, the primary outcome was patient death and the secondary outcome was tumor recurrence. Continuous variables were expressed as means and medians and were compared using the Student t test if normally distributed or Wilcoxon-Mann-Whitney test for nonparametric variables. Discrete variables were expressed as frequency and percentages and χ(2) or Fisher exact test, when appropriate, were used for comparisons. Kaplan-Meier curves were used to calculate the probability of survival and comparisons were performed using log-rank test. Results: In this study, compared with the open group, the robotic group had a longer operation time ( (338±71) minutes vs. (256±56) minutes, t=4.251, P=0.001) , but the intraoperative blood loss was less (100 ml vs. 200 ml, Z=121.50, P=0.040) , the gastric tube removal time was earlier (3 days vs. 4 days, Z=136.0, P=0.011) , and the postoperative hospital stay was shorter (9 days vs. 12 days, Z=144.50, P=0.040) , and the difference was statistically significant.There was no significant difference in the blood transfusion rate, R0 resection rate, and tumor size between the two groups.The recurrence rates in the robotic group and open surgery were 53.3% and 67.0%, respectively (χ(2)=1.04, P=0.307) .The median survival time of the robotic group and the open group was 22.0 months and 25.0 months. There was no significant difference in the overall survival rate between the two groups (P>0.05) . Conclusion: Compared with laparotomy, robotic HCC radical resection could have an equivalence or non-inferiority approach with acceptable long-term outcome.
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Affiliation(s)
- S Chou
- Second Department of Hepatobiliary Surgery, the First Medical Center of People's Liberation Army General Hospital, Beijing 100853, China
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15
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Natori Y, Alghamdi A, Tazari M, Miller V, Husain S, Komatsu T, Griffiths P, Ljungman P, Orchanian-Cheff A, Kumar D, Humar A, Alexander B, Avery R, Baldanti F, Barnett S, Baum P, Berrey MM, Birnkrant D, Blumberg E, Boeckh M, Boutolleau D, Bowlin T, Brooks J, Chemaly R, Chou S, Cloherty G, Cruikshank W, Dropulic L, Einsele H, Erdman J, Fahle G, Fallon L, Gillis H, Gonzalez D, Griffiths P, Gunter K, Hirsch H, Hodowanec A, Humar A, Hunt P, Josephson F, Komatsu T, Kotton C, Krause P, Kuhr F, Lademacher C, Lanier R, Lazarus T, Leake J, Leavitt R, Lehrman SN, Li L, Ljungman P, Lodding PI, Lundgren J, Martinez-Murillo F(P, Mayer H, McCutcheon M, McKinnon J, Mertens T, Miller V, Modarress K, Mols J, Mossman S, Murata Y, Murawski D, Murray J, Natori Y, Nichols G, O’Rear J, Peggs K, Pikis A, Prichard M, Razonable R, Riches M, Roberts J, Saber W, Sayada C, Singer M, Stamminger T, Wijatyk A, Yu D, Zeiher B. Use of Viral Load as a Surrogate Marker in Clinical Studies of Cytomegalovirus in Solid Organ Transplantation: A Systematic Review and Meta-analysis. Clin Infect Dis 2019; 66:617-631. [PMID: 29020339 DOI: 10.1093/cid/cix793] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 09/01/2017] [Indexed: 12/22/2022] Open
Abstract
Symptomatic cytomegalovirus (CMV) disease has been the standard endpoint for clinical trials in organ transplant recipients. Viral load may be a more relevant endpoint due to low frequency of disease. We performed a meta-analysis and systematic review of the literature. We found several lines of evidence to support the validity of viral load as an appropriate surrogate end-point, including the following: (1) viral loads in CMV disease are significantly greater than in asymptomatic viremia (odds ratio, 9.3 95% confidence interval, 4.6-19.3); (2) kinetics of viral replication are strongly associated with progression to disease; (3) pooled incidence of CMV viremia and disease is significantly lower during prophylaxis compared with the full patient follow-up period (viremia incidence: 3.2% vs 34.3%; P < .001) (disease incidence: 1.1% vs 13.0%; P < .001); (4) treatment of viremia prevented disease; and (5) viral load decline correlated with symptom resolution. Based on the analysis, we conclude that CMV load is an appropriate surrogate endpoint for CMV trials in organ transplant recipients.
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Affiliation(s)
- Yoichiro Natori
- Multi-Organ Transplant Program, University Health Network, Toronto, Ontario, Canada
| | - Ali Alghamdi
- Multi-Organ Transplant Program, University Health Network, Toronto, Ontario, Canada.,King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Mahmood Tazari
- Multi-Organ Transplant Program, University Health Network, Toronto, Ontario, Canada
| | - Veronica Miller
- Forum for Collaborative Research, University of California, Berkeley
| | - Shahid Husain
- Multi-Organ Transplant Program, University Health Network, Toronto, Ontario, Canada
| | - Takashi Komatsu
- Division of Antiviral Products, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland
| | - Paul Griffiths
- Institute for Immunity and Transplantation, University College London Medical School, United Kingdom
| | - Per Ljungman
- Division of Hematology, Department of Medicine Huddigne, Karolinksa Institutet, Stockholm, Sweden
| | - Ani Orchanian-Cheff
- Library and Information Services, University Health Network, Toronto, Ontario, Canada
| | - Deepali Kumar
- Multi-Organ Transplant Program, University Health Network, Toronto, Ontario, Canada
| | - Atul Humar
- Multi-Organ Transplant Program, University Health Network, Toronto, Ontario, Canada
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16
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Chou S, Wu J, Song K, Bo T. Novel UL97 drug resistance mutations identified at baseline in a clinical trial of maribavir for resistant or refractory cytomegalovirus infection. Antiviral Res 2019; 172:104616. [PMID: 31568799 DOI: 10.1016/j.antiviral.2019.104616] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/26/2019] [Accepted: 09/26/2019] [Indexed: 12/27/2022]
Abstract
In a Phase 2 clinical trial, 120 subjects with cytomegalovirus (CMV) infection refractory or resistant to standard therapy were randomized equally to 3 doses of oral maribavir treatment, and 70% achieved undetectable plasma CMV DNA within 12 weeks. At study entry, standard diagnostic UL97 genotyping was available for 71 subjects, with 60 (85%) revealing well-characterized ganciclovir resistance mutations that did not preclude a therapeutic response to maribavir. Central laboratory testing of a range of UL97 codons (288-468) not fully covered by standard genotyping was done on 93 subjects at baseline. This detected no previously known maribavir resistance mutations, but identified atypical mutations in 3 subjects, including a P-loop substitution F342Y, and ATP-binding region substitutions K359E/Q. By recombinant phenotyping, K359E and K359Q each conferred a nearly 4-fold increased ganciclovir 50% inhibitory concentration (EC50) without maribavir resistance, whereas F342Y conferred a 6-fold increased ganciclovir EC50 and a 4.5-fold increased maribavir EC50. The subject with F342Y detected at baseline did not achieve plasma CMV DNA clearance after 12 weeks of maribavir therapy and later developed an additional UL97 substitution H411Y known to confer 12- to 20-fold increased MBV EC50 by itself. The combination of F342Y and H411Y was shown to increase the maribavir EC50 by 56-fold. Diagnostic genotyping of UL97 should be expanded to cover the ATP-binding region beginning at codon 335 to enable the detection of atypical resistance mutations and further correlation of their clinical significance.
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Affiliation(s)
- Sunwen Chou
- Division of Infectious Diseases, Oregon Health and Science University, Department of Veterans Affairs Medical Center, Portland, Oregon, USA.
| | | | | | - Tien Bo
- Shire, a Takeda Company, Lexington, MA, USA
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17
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Huang T, Li S, Chen Y, Lu H, Lo C, Fang F, Chou S, Wang Y. PO-0799 Treatment outcomes of nodal positive unresectable thoracic esophageal carcinoma. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(19)31219-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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18
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Liu RC, Consuegra G, Chou S, Fernandez Peñas P. Vitiligo-like depigmentation in oncology patients treated with immunotherapies for nonmelanoma metastatic cancers. Clin Exp Dermatol 2019; 44:643-646. [PMID: 30618056 DOI: 10.1111/ced.13867] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/2018] [Indexed: 11/29/2022]
Abstract
Vitiligo-like depigmentation (VLD) is a characteristic cutaneous event described in patients with metastatic malignant melanoma receiving treatment with immune checkpoint inhibitors. We report the onset of VLD in three patients with other cancer types (cholangiocarcinoma, renal cell carcinoma and squamous cell carcinoma) following treatment with immunotherapy (combination pembrolizumab and nivolumab for the first, and pembrolizumab for the other two cancer types). Cases of VLD have not been reported previously in patients treated for any of these cancers, to our knowledge. Pembrolizumab and nivolumab are monoclonal antibodies targeting programmed cell death (PD)-1 receptors, while ipilimumab targets cytotoxic T-lymphocyte antigen-4. Our clinical finding challenges the current understanding of VLD as a malignant melanoma-specific immunotherapy-related adverse event.
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Affiliation(s)
- R C Liu
- Department of Dermatology, Westmead Hospital, Sydney, Australia.,Westmead Clinical School, the University of Sydney Medical School, Sydney, Australia
| | - G Consuegra
- Department of Dermatology, Westmead Hospital, Sydney, Australia.,Westmead Clinical School, the University of Sydney Medical School, Sydney, Australia
| | - S Chou
- Tissue Pathology and Diagnostic Oncology, Westmead Hospital, Sydney, Australia
| | - P Fernandez Peñas
- Department of Dermatology, Westmead Hospital, Sydney, Australia.,Westmead Clinical School, the University of Sydney Medical School, Sydney, Australia
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19
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Cherrier L, Nasar A, Goodlet KJ, Nailor MD, Tokman S, Chou S. Emergence of letermovir resistance in a lung transplant recipient with ganciclovir-resistant cytomegalovirus infection. Am J Transplant 2018; 18:3060-3064. [PMID: 30286286 PMCID: PMC6263820 DOI: 10.1111/ajt.15135] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 09/25/2018] [Accepted: 09/27/2018] [Indexed: 01/25/2023]
Abstract
Following a year of valganciclovir prophylaxis, a lung transplant recipient developed cytomegalovirus (CMV) infection that became resistant to ganciclovir, as confirmed by detection of UL97 kinase mutation M460V and a previously uncharacterized UL54 DNA polymerase mutation L516P. The latter mutation is now shown to confer ganciclovir and cidofovir resistance. As predicted from the viral genotype, foscarnet therapy was effective, but resumption of valganciclovir as secondary prophylaxis resulted in a plasma viral load rebound to 3.6 log10 copies/mL several weeks later. Valganciclovir was then replaced by letermovir, resulting in gradual viral load reduction in the first 5 weeks to below the quantitation limit (2.7 log10 copies/mL) for 1 week, followed by 10 weeks of rising viral loads reaching 4.3 log10 copies/mL while on letermovir. At this point, CMV genotypic testing revealed UL56 mutation C325Y, which confers absolute resistance to letermovir. Retreatment with foscarnet was successful. This case adds to the considerable list of proven ganciclovir resistance mutations, and provides an early experience with letermovir resistance after off-label therapeutic use. This experience is consistent with in vitro observations of rapid emergence of letermovir-resistant CMV after drug exposure.
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Affiliation(s)
- Lauren Cherrier
- Department of Pharmacy Services, Dignity Health, St. Joseph’s Hospital and Medical Center, Phoenix, Arizona, USA
| | - Aasya Nasar
- Department of Pharmacy Services, Dignity Health, St. Joseph’s Hospital and Medical Center, Phoenix, Arizona, USA
| | - Kellie J. Goodlet
- Department of Pharmacy Practice, College of Pharmacy, Midwestern University, Glendale, Arizona, USA
| | - Michael D. Nailor
- Department of Pharmacy Services, Dignity Health, St. Joseph’s Hospital and Medical Center, Phoenix, Arizona, USA
| | - Sofya Tokman
- Division of Transplant Pulmonology, Norton Thoracic Institute, Dignity Health, St. Joseph’s Hospital and Medical Center, Phoenix, Arizona, USA
| | - Sunwen Chou
- Oregon Health & Science University and Portland VA Health Care System, Oregon, USA
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20
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Chou S, Ercolani RJ, Derakhchan K. Antiviral activity of maribavir in combination with other drugs active against human cytomegalovirus. Antiviral Res 2018; 157:128-133. [PMID: 30040968 PMCID: PMC6097806 DOI: 10.1016/j.antiviral.2018.07.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 07/15/2018] [Accepted: 07/19/2018] [Indexed: 12/11/2022]
Abstract
The human cytomegalovirus (CMV) UL97 kinase inhibitor maribavir is in Phase III clinical trials as antiviral therapy, including use for infections refractory or resistant to standard therapy. To assess its activity in combination with approved and experimental CMV antivirals, and with the mTor inhibitor rapamycin (sirolimus), drug effects were tested by in vitro checkerboard assays and the data were analyzed using a three dimensional model based on an independent effects definition of additive interactions. Baseline virus and representative drug-resistant mutants were tested. According to the volume of synergy at 95% confidence, maribavir showed additive interactions with foscarnet, cidofovir, letermovir and GW275175X when tested against wild type and mutant viruses, strong antagonism with ganciclovir, and strong synergy with rapamycin, the latter suggesting a potentially useful therapeutic combination.
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Affiliation(s)
- Sunwen Chou
- Division of Infectious Diseases, Oregon Health & Science University, USA; Portland Veterans Affairs Health Care System, OR USA.
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21
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Chou S. A third component of the human cytomegalovirus terminase complex is involved in letermovir resistance. Antiviral Res 2017; 148:1-4. [PMID: 29107686 DOI: 10.1016/j.antiviral.2017.10.019] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 10/23/2017] [Accepted: 10/27/2017] [Indexed: 12/17/2022]
Abstract
Letermovir is a human cytomegalovirus (CMV) terminase inhibitor that was clinically effective in a Phase III prevention trial. In vitro studies have shown that viral mutations conferring letermovir resistance map primarily to the UL56 component of the terminase complex and uncommonly to UL89. After serial culture of a baseline CMV laboratory strain under letermovir, mutation was observed in a third terminase component in 2 experiments, both resulting in amino acid substitution P91S in gene UL51 and adding to a pre-existing UL56 mutation. Recombinant phenotyping indicated that P91S alone conferred 2.1-fold increased letermovir resistance (EC50) over baseline, and when combined with UL56 mutation S229F or R369M, multiplied the level of resistance conferred by those mutations by 3.5-7.7-fold. Similarly a combination of UL56 mutations S229F, L254F and L257I selected in the same experiment conferred 54-fold increased letermovir EC50 over baseline, but 290-fold when combined with UL51 P91S. The P91S mutant was not perceptibly growth impaired. Although pUL51 is essential for normal function of the terminase complex, its biological significance is not well understood. Letermovir resistance mutations mapping to 3 separate genes, and their multiplier effect on the level of resistance, suggest that the terminase components interactively contribute to the structure of a letermovir antiviral target. The diagnostic importance of the UL51 P91S mutation arises from its potential to augment the letermovir resistance of some UL56 mutations at low fitness cost.
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Affiliation(s)
- Sunwen Chou
- Division of Infectious Diseases, Oregon Health and Science University, Department of Veterans Affairs Medical Center, Portland, OR, USA.
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22
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Chandraratnam E, Santos L, Chou S, Dai J, Syeda L, Eslick G, Chin R. Remote frozen section examination of parathyroidectomy specimens by telepathology using Mikroscan D2 and Aperio LV1: a validation study. Intern Med J 2017. [DOI: 10.1111/imj.3_13457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - L Santos
- South Western Area Pathology Service (SWAPS); Liverpool Hospital; Australia
| | - S Chou
- Institute of Clinical Pathology and Medical Research (ICPMR); Westmead Hospital; Australia
| | - J Dai
- Nepean Hospital; Kingswood New South Wales Australia
| | - L Syeda
- Austpath Laboratories; Northmead New South Wales Australia
| | - G Eslick
- The University of Sydney and the Mann Whitney Institute; Australia
| | - R Chin
- Nepean Hospital; Kingswood New South Wales Australia
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23
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Lo W, Chuang J, Ko C, Chou S, Chen R, Chang K, Hung J, Su W, Chang W, Hsu T. P05.06 Upregulation of CYP17A1 by Sp1-mediated DNA demethylation confers temozolomide resistance through DHEA-mediated protection in glioma. Neuro Oncol 2017. [DOI: 10.1093/neuonc/nox036.173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Chou S. Foscarnet resistance mutations mapping to atypical domains of the cytomegalovirus DNA polymerase gene. Antiviral Res 2016; 138:57-60. [PMID: 27940027 DOI: 10.1016/j.antiviral.2016.12.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 11/29/2016] [Accepted: 12/05/2016] [Indexed: 12/26/2022]
Abstract
Human cytomegalovirus UL54 DNA polymerase gene mutations that confer foscarnet resistance in clinical practice typically cluster in the amino terminal 2, palm and finger domains. Exposure to foscarnet in cell culture selected for mutations elsewhere in UL54, including amino acid substitutions S290R in the amino terminal 1 domain and E951D in the palm 2 domain. These are newly confirmed to confer foscarnet resistance and slightly decreased ganciclovir susceptibility. Other emergent substitutions N495K, T552N and T838A are known to confer foscarnet resistance, while additional ones Q783R and V798A only slightly affected susceptibility. An expanded set of domains is involved in foscarnet resistance and its genotypic diagnosis.
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Affiliation(s)
- Sunwen Chou
- Division of Infectious Diseases, Oregon Health and Science University, Portland, OR, USA; Department of Veterans Affairs Medical Center, Portland, OR, USA.
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Chou S, Xu J, Khrennikov K, Cardenas DE, Wenz J, Heigoldt M, Hofmann L, Veisz L, Karsch S. Collective Deceleration of Laser-Driven Electron Bunches. Phys Rev Lett 2016; 117:144801. [PMID: 27740829 DOI: 10.1103/physrevlett.117.144801] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Indexed: 06/06/2023]
Abstract
Few-fs electron bunches from laser wakefield acceleration (LWFA) can efficiently drive plasma wakefields (PWFs), as shown by their propagation through underdense plasma in two experiments. A strong and density-insensitive deceleration of the bunches has been observed in 2 mm of 10^{18} cm^{-3} density plasma with 5.1 GV/m average gradient, which is attributed to a self-driven PWF. This observation implies that the physics of PWFs, usually relying on large-scale rf accelerators as drivers, can be studied by tabletop LWFA electron sources.
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Affiliation(s)
- S Chou
- Max-Planck Institut für Quantenoptik, 85748 Garching, Germany
- Department für Physik, Ludwig-Maximilians Universität, 85748 Garching, Germany
| | - J Xu
- Max-Planck Institut für Quantenoptik, 85748 Garching, Germany
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P. O. Box 800-211, Shanghai 201800, China
| | - K Khrennikov
- Department für Physik, Ludwig-Maximilians Universität, 85748 Garching, Germany
| | - D E Cardenas
- Max-Planck Institut für Quantenoptik, 85748 Garching, Germany
- Department für Physik, Ludwig-Maximilians Universität, 85748 Garching, Germany
| | - J Wenz
- Department für Physik, Ludwig-Maximilians Universität, 85748 Garching, Germany
| | - M Heigoldt
- Department für Physik, Ludwig-Maximilians Universität, 85748 Garching, Germany
| | - L Hofmann
- Max-Planck Institut für Quantenoptik, 85748 Garching, Germany
- Department für Physik, Ludwig-Maximilians Universität, 85748 Garching, Germany
| | - L Veisz
- Max-Planck Institut für Quantenoptik, 85748 Garching, Germany
- Department of Physics, Umeå University, SE-901 87 Umeå, Sweden
| | - S Karsch
- Max-Planck Institut für Quantenoptik, 85748 Garching, Germany
- Department für Physik, Ludwig-Maximilians Universität, 85748 Garching, Germany
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Hutterer C, Hamilton S, Steingruber M, Zeitträger I, Bahsi H, Thuma N, Naing Z, Örfi Z, Örfi L, Socher E, Sticht H, Rawlinson W, Chou S, Haupt VJ, Marschall M. The chemical class of quinazoline compounds provides a core structure for the design of anticytomegaloviral kinase inhibitors. Antiviral Res 2016; 134:130-143. [PMID: 27515131 DOI: 10.1016/j.antiviral.2016.08.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 07/28/2016] [Accepted: 08/05/2016] [Indexed: 12/26/2022]
Abstract
HCMV is a member of the family Herpesviridae and represents a worldwide distributed pathogen with seropositivity rates in the adult population ranging between 40% and 90%. Notably, HCMV infection is a serious, sometimes life-threatening medical problem for newborns and immunosuppressed individuals, including transplant recipients and patients under antitumoral chemotherapy. Current standard therapy with valganciclovir has the disadvantage of inducing drug-resistant virus mutants and toxicity-related side effects. Our analysis stresses the earlier finding that kinase inhibitors of the quinazoline class exert an antiviral response by targeting the viral protein kinase pUL97 without inducing resistance. Therefore, quinazolines have been used as a core structure to gain insight in the mode of inhibitor-kinase interaction. Here, we demonstrate that (i) the novel quinazolines Vi7392 and Vi7453 are highly active against HCMV laboratory and clinically relevant strains including maribavir- and ganciclovir-resistant variants, (ii) antiviral activity is not cell-type specific and was also detected in a placental explant tissue model using a genetically intact HCMV strain (iii) the viral kinase pUL97 represents a target of the anticytomegaloviral activity of these compounds, (iv) induction of pUL97-conferring drug resistance was not detectable under single-step selection, thus differed from the induction of ganciclovir resistance, and (v) pUL97 drug docking simulations enabled detailed insights into specific drug-target binding properties providing a promising basis for the design of optimized kinase inhibitors. These novel findings may open new prospects for the future medical use of quinazoline drug candidates and the use of drug-target dynamic simulations for rational design of antivirals.
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Affiliation(s)
- C Hutterer
- Institute of Clinical and Molecular Virology, Friedrich-Alexander University (FAU) of Erlangen-Nürnberg, Erlangen, Germany.
| | - S Hamilton
- Serology and Virology Division, SEALS Microbiology Prince of Wales Hospital Randwick NSW 2013 and SOMS and BABS, University of NSW, Sydney, Australia
| | - M Steingruber
- Institute of Clinical and Molecular Virology, Friedrich-Alexander University (FAU) of Erlangen-Nürnberg, Erlangen, Germany
| | - I Zeitträger
- Institute of Clinical and Molecular Virology, Friedrich-Alexander University (FAU) of Erlangen-Nürnberg, Erlangen, Germany
| | - H Bahsi
- Institute of Clinical and Molecular Virology, Friedrich-Alexander University (FAU) of Erlangen-Nürnberg, Erlangen, Germany
| | - N Thuma
- Institute of Clinical and Molecular Virology, Friedrich-Alexander University (FAU) of Erlangen-Nürnberg, Erlangen, Germany
| | - Z Naing
- Serology and Virology Division, SEALS Microbiology Prince of Wales Hospital Randwick NSW 2013 and SOMS and BABS, University of NSW, Sydney, Australia
| | - Z Örfi
- Department of Molecular Biology, Max-Planck-Institute of Biochemistry, Martinsried, Germany
| | - L Örfi
- Semmelweis University, Department of Pharmaceutical Chemistry, Budapest, Hungary
| | - E Socher
- Division of Bioinformatics, Institute of Biochemistry, FAU of Erlangen-Nürnberg, Erlangen, Germany
| | - H Sticht
- Division of Bioinformatics, Institute of Biochemistry, FAU of Erlangen-Nürnberg, Erlangen, Germany
| | - W Rawlinson
- Serology and Virology Division, SEALS Microbiology Prince of Wales Hospital Randwick NSW 2013 and SOMS and BABS, University of NSW, Sydney, Australia
| | - S Chou
- Division of Infectious Diseases, Oregon Health and Science University and VA Medical Center, Portland, USA
| | - V J Haupt
- Biotechnology Center, Technische Universität Dresden, Dresden, Germany
| | - M Marschall
- Institute of Clinical and Molecular Virology, Friedrich-Alexander University (FAU) of Erlangen-Nürnberg, Erlangen, Germany
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Chou S, Yang C, Lo Y. Fetal Mesenchymal Stem Cells Exhibit a Wnt-dependent Protective Action on Radiation-induced Hematopoietic Failure. Cytotherapy 2016. [DOI: 10.1016/j.jcyt.2016.03.232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Lanier ER, Foster S, Brundage T, Chou S, Prichard MN, Kleiboeker S, Wilson C, Colville D, Mommeja-Marin H. Analysis of Mutations in the Gene Encoding Cytomegalovirus DNA Polymerase in a Phase 2 Clinical Trial of Brincidofovir Prophylaxis. J Infect Dis 2016; 214:32-5. [PMID: 26941282 PMCID: PMC4907407 DOI: 10.1093/infdis/jiw073] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 02/16/2016] [Indexed: 11/26/2022] Open
Abstract
Brincidofovir is an oral antiviral in development for prevention of cytomegalovirus disease. Cytomegalovirus genotyping results from a phase 2 trial comparing brincidofovir to placebo for prophylaxis against cytomegalovirus infection in hematopoietic cell transplant recipients provided initial data on the clinical resistance profile for brincidofovir. In this study, no known resistance-associated mutations were detected in brincidofovir-treated subjects; identified genotypic substitutions did not confer resistance to cytomegalovirus antivirals in vitro, suggesting that these changes represent polymorphisms unrelated to brincidofovir resistance. Lack of evidence for genotypic resistance during prophylaxis suggests that first-line use of brincidofovir for prevention of cytomegalovirus infection may preserve downstream options for patients.
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Affiliation(s)
| | | | | | - Sunwen Chou
- Division of Infectious Diseases, Oregon Health and Science University Department of Veterans Affairs Medical Center, Portland, Oregon
| | - Mark N Prichard
- Department of Pediatrics, University of Alabama at Birmingham
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Iwahori S, Hakki M, Chou S, Kalejta RF. Molecular Determinants for the Inactivation of the Retinoblastoma Tumor Suppressor by the Viral Cyclin-dependent Kinase UL97. J Biol Chem 2015; 290:19666-80. [PMID: 26100623 DOI: 10.1074/jbc.m115.660043] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Indexed: 01/10/2023] Open
Abstract
The retinoblastoma (Rb) tumor suppressor restricts cell cycle progression by repressing E2F-responsive transcription. Cellular cyclin-dependent kinase (CDK)-mediated Rb inactivation through phosphorylation disrupts Rb-E2F complexes, stimulating transcription. The human cytomegalovirus (HCMV) UL97 protein is a viral CDK (v-CDK) that phosphorylates Rb. Here we show that UL97 phosphorylates 11 of the 16 consensus CDK sites in Rb. A cleft within Rb accommodates peptides with the amino acid sequence LXCXE. UL97 contains three such motifs. We determined that the first LXCXE motif (L1) of UL97 and the Rb cleft enhance UL97-mediated Rb phosphorylation. A UL97 mutant with a non-functional L1 motif (UL97-L1m) displayed significantly reduced Rb phosphorylation at multiple sites. Curiously, however, it efficiently disrupted Rb-E2F complexes but failed to relieve Rb-mediated repression of E2F reporter constructs. The HCMV immediate early 1 protein cooperated with UL97-L1m to inactivate Rb in transfection assays, likely indicating that cells infected with a UL97-L1m mutant virus show no defects in growth or E2F-responsive gene expression because of redundant viral mechanisms to inactivate Rb. Our data suggest that UL97 possesses a mechanism to elicit E2F-dependent gene expression distinct from disruption of Rb-E2F complexes and dependent upon both the L1 motif of UL97 and the cleft region of Rb.
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Affiliation(s)
- Satoko Iwahori
- From the Institute for Molecular Virology and McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin 53706 and
| | - Morgan Hakki
- the Division of Infectious Diseases, Oregon Health and Science University and
| | - Sunwen Chou
- the Division of Infectious Diseases, Oregon Health and Science University and Veterans Affairs Portland Health Care System, Portland, Oregon 97239
| | - Robert F Kalejta
- From the Institute for Molecular Virology and McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin 53706 and
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Chou S, Boivin G, Ives J, Elston R. Phenotypic evaluation of previously uncharacterized cytomegalovirus DNA polymerase sequence variants detected in a valganciclovir treatment trial. J Infect Dis 2013; 209:1219-26. [PMID: 24273181 DOI: 10.1093/infdis/jit654] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND In a large randomized trial comparing oral valganciclovir and intravenous ganciclovir for treatment of cytomegalovirus disease in solid organ transplantation, confirmed genotypic drug resistance was uncommon (<5%), but definitive interpretation was limited by the detection of 110 uncharacterized UL54 viral DNA polymerase sequence variants. METHODS Based on treatment history and genetic locus of the sequence changes, 39 of the sequence variants were prioritized for recombinant phenotyping by construction of cloned viral mutants and drug susceptibility testing in cell culture. RESULTS Four amino acid substitutions were newly confirmed to alter ganciclovir susceptibility: A505V and I726T conferred a borderline decrease in ganciclovir and cidofovir susceptibility, while Q578L and G841S conferred slightly decreased ganciclovir and foscarnet susceptibility. A nonviable phenotype was found for 8 mutations distributed among amino terminal, exonuclease and catalytic domains. Retesting of stored study specimens could not confirm the original detection of >20 sequence variants, including the nonviable mutations and several resistance mutations. CONCLUSIONS Newly phenotyped UL54 sequence variants did not significantly change the reported incidence of drug resistance in the clinical trial. Unrecognized sequence variants in diagnostic genotyping reports should be confirmed by additional testing in order to improve clinical decision making.
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Affiliation(s)
- Sunwen Chou
- Division of Infectious Disease, Oregon Health and Science University and VA Medical Center, Portland
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Heck O, Anxionnat R, Bracard S, Cai X, Han S, Feske S, Chou S. Pearls & Oy-sters: Small but consequential: Intracerebral hemorrhage caused by lenticulostriate artery aneurysm. Neurology 2013; 81:1881. [DOI: 10.1212/01.wnl.0000435757.50996.ae] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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32
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Molgat-Seon Y, Daboval T, Chou S, Jay O. Accidental overheating of a newborn under an infant radiant warmer: a lesson for future use. J Perinatol 2013; 33:738-9. [PMID: 23986092 DOI: 10.1038/jp.2013.32] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 01/30/2013] [Accepted: 02/21/2013] [Indexed: 11/09/2022]
Abstract
A fully functional radiant warmer induced rapid and continuous increases in regional skin temperatures, heart rate, mean arterial blood pressure and respiratory rate in a newborn patient without corrective action. We report this case of passive overheating to create awareness of the risks associated with regulating radiant heat output based upon a single servo-controlled temperature.
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Affiliation(s)
- Y Molgat-Seon
- Thermal Ergonomics Laboratory, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada
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Kotton CN, Kumar D, Caliendo AM, Asberg A, Chou S, Danziger-Isakov L, Humar A. Updated international consensus guidelines on the management of cytomegalovirus in solid-organ transplantation. Transplantation 2013; 96:333-60. [PMID: 23896556 DOI: 10.1097/tp.0b013e31829df29d] [Citation(s) in RCA: 549] [Impact Index Per Article: 49.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cytomegalovirus (CMV) continues to be one of the most common infections after solid-organ transplantation, resulting in significant morbidity, graft loss, and adverse outcomes. Management of CMV varies considerably among transplant centers but has been become more standardized by publication of consensus guidelines by the Infectious Diseases Section of The Transplantation Society. An international panel of experts was reconvened in October 2012 to revise and expand evidence and expert opinion-based consensus guidelines on CMV management, including diagnostics, immunology, prevention, treatment, drug resistance, and pediatric issues. The following report summarizes the recommendations.
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Affiliation(s)
- Camille N Kotton
- Transplant and Immunocompromised Host Infectious Diseases, Infectious Diseases Division, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA.
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Vigant F, Lee J, Hollmann A, Tanner LB, Akyol Ataman Z, Yun T, Shui G, Aguilar HC, Zhang D, Meriwether D, Roman-Sosa G, Robinson LR, Juelich TL, Buczkowski H, Chou S, Castanho MARB, Wolf MC, Smith JK, Banyard A, Kielian M, Reddy S, Wenk MR, Selke M, Santos NC, Freiberg AN, Jung ME, Lee B. A mechanistic paradigm for broad-spectrum antivirals that target virus-cell fusion. PLoS Pathog 2013; 9:e1003297. [PMID: 23637597 PMCID: PMC3630091 DOI: 10.1371/journal.ppat.1003297] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 02/24/2013] [Indexed: 12/20/2022] Open
Abstract
LJ001 is a lipophilic thiazolidine derivative that inhibits the entry of numerous enveloped viruses at non-cytotoxic concentrations (IC50≤0.5 µM), and was posited to exploit the physiological difference between static viral membranes and biogenic cellular membranes. We now report on the molecular mechanism that results in LJ001's specific inhibition of virus-cell fusion. The antiviral activity of LJ001 was light-dependent, required the presence of molecular oxygen, and was reversed by singlet oxygen (1O2) quenchers, qualifying LJ001 as a type II photosensitizer. Unsaturated phospholipids were the main target modified by LJ001-generated 1O2. Hydroxylated fatty acid species were detected in model and viral membranes treated with LJ001, but not its inactive molecular analog, LJ025. 1O2-mediated allylic hydroxylation of unsaturated phospholipids leads to a trans-isomerization of the double bond and concurrent formation of a hydroxyl group in the middle of the hydrophobic lipid bilayer. LJ001-induced 1O2-mediated lipid oxidation negatively impacts on the biophysical properties of viral membranes (membrane curvature and fluidity) critical for productive virus-cell membrane fusion. LJ001 did not mediate any apparent damage on biogenic cellular membranes, likely due to multiple endogenous cytoprotection mechanisms against phospholipid hydroperoxides. Based on our understanding of LJ001's mechanism of action, we designed a new class of membrane-intercalating photosensitizers to overcome LJ001's limitations for use as an in vivo antiviral agent. Structure activity relationship (SAR) studies led to a novel class of compounds (oxazolidine-2,4-dithiones) with (1) 100-fold improved in vitro potency (IC50<10 nM), (2) red-shifted absorption spectra (for better tissue penetration), (3) increased quantum yield (efficiency of 1O2 generation), and (4) 10–100-fold improved bioavailability. Candidate compounds in our new series moderately but significantly (p≤0.01) delayed the time to death in a murine lethal challenge model of Rift Valley Fever Virus (RVFV). The viral membrane may be a viable target for broad-spectrum antivirals that target virus-cell fusion. The threat of emerging and re-emerging viruses underscores the need to develop broad-spectrum antivirals. LJ001 is a non-cytotoxic, membrane-targeted, broad-spectrum antiviral previously reported to inhibit the entry of many lipid-enveloped viruses. Here, we delineate the molecular mechanism that underlies LJ001's antiviral activity. LJ001 generates singlet oxygen (1O2) in the membrane bilayer; 1O2-mediated lipid oxidation results in changes to the biophysical properties of the viral membrane that negatively impacts its ability to undergo virus-cell fusion. These changes are not apparent on LJ001-treated cellular membranes due to their repair by cellular lipid biosynthesis. Thus, we generated a new class of membrane-targeted broad-spectrum antivirals with improved photochemical, photophysical, and pharmacokinetic properties leading to encouraging in vivo efficacy against a lethal emerging pathogen. This study provides a mechanistic paradigm for the development of membrane-targeting broad-spectrum antivirals that target the biophysical process underlying virus-cell fusion and that exploit the difference between inert viral membranes and their biogenic cellular counterparts.
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Affiliation(s)
- Frederic Vigant
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, California, United States of America
| | - Jihye Lee
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Axel Hollmann
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisbon, Portugal
| | - Lukas B. Tanner
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- NUS Graduate School for Integrative Sciences and Engineering (NGS), National University of Singapore, Singapore
| | - Zeynep Akyol Ataman
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, California, United States of America
| | - Tatyana Yun
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Guanghou Shui
- Life Sciences Institute, National University of Singapore, Singapore
| | - Hector C. Aguilar
- Paul G. Allen School for Global Animal Health, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, United States of America
| | - Dong Zhang
- Department of Chemistry and Biochemistry, California State University, Los Angeles, California, United States of America
| | - David Meriwether
- Department of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Gleyder Roman-Sosa
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Lindsey R. Robinson
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, California, United States of America
| | - Terry L. Juelich
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Hubert Buczkowski
- Wildlife Zoonoses and Vector Borne Disease Research Group, Animal Health and Veterinary Laboratories Agency, Weybridge, Surrey, United Kingdom
| | - Sunwen Chou
- Oregon Health & Science University and VA Medical Center, Portland, Oregon, United States of America
| | - Miguel A. R. B. Castanho
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisbon, Portugal
| | - Mike C. Wolf
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, California, United States of America
| | - Jennifer K. Smith
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Ashley Banyard
- Wildlife Zoonoses and Vector Borne Disease Research Group, Animal Health and Veterinary Laboratories Agency, Weybridge, Surrey, United Kingdom
| | - Margaret Kielian
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Srinivasa Reddy
- Department of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Markus R. Wenk
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
- Swiss Tropical and Public Health Institute and University of Basel, Basel, Switzerland
| | - Matthias Selke
- Department of Chemistry and Biochemistry, California State University, Los Angeles, California, United States of America
| | - Nuno C. Santos
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisbon, Portugal
| | - Alexander N. Freiberg
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Michael E. Jung
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Benhur Lee
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail:
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Mohd Affandi A, Anforth R, Chou S, Fernadez-Peñas P. Non-evolving linear facial plaque. Clin Exp Dermatol 2013; 38:681-3. [PMID: 23581846 DOI: 10.1111/ced.12023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/28/2012] [Indexed: 11/28/2022]
Affiliation(s)
- A Mohd Affandi
- Department of Dermatology, Westmead Hospital, New South Wales, Australia
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36
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Goosen MF, O'Shea GM, Gharapetian HM, Chou S, Sun AM. Optimization of microencapsulation parameters: Semipermeable microcapsules as a bioartificial pancreas. Biotechnol Bioeng 2012; 27:146-50. [PMID: 18553649 DOI: 10.1002/bit.260270207] [Citation(s) in RCA: 272] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
An improved membrane has been developed for the microencapsulation of islets of Langerhans which protects these cells from the immune system. These requirements were accomplished through the optimization of important microencapsulation parameters and through the improved biocompatibility of a new alginate-poly-l-lysine (PLL)-alginate capsule membrane. Spherical and smooth microcapsules could be formed by utilizing a purer sodium alginate and by keeping the viscosity of the sodium alginate solution above 30 cps. The strength of the capsule membrane was enhanced by increasing the alginate-PLL reaction time as well as the PLL concentration. The permeability of the membrane [4 mum thick, 93% (w/w) water] was a function of the viscosity average molecular weight (Mv) of the PLL (Mv = 4000-4 x 10(5)) used in the encapsulation procedure. Microcapsules prepared with PLL with Mv = 1.7 x 10(4) were the least permeable, being impermeable to normal serum immunoglobulin, albumin, and haemoglobin. The microencapsulation procedure, by protecting transplanted tissue from the components of the immune system, has great clinical potential as a new form of treatment for diseases such as diabetes and liver disease.
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Affiliation(s)
- M F Goosen
- Connaught Research Institute, 1755 Steeles Avenue West, Willowdale, Ontario M2N 3T4 Canada
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Chou S, Hakki M, Villano S. Effects on maribavir susceptibility of cytomegalovirus UL97 kinase ATP binding region mutations detected after drug exposure in vitro and in vivo. Antiviral Res 2012; 95:88-92. [PMID: 22664236 DOI: 10.1016/j.antiviral.2012.05.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Revised: 05/16/2012] [Accepted: 05/24/2012] [Indexed: 11/25/2022]
Abstract
Resistance to the experimental human cytomegalovirus (CMV) UL97 kinase inhibitor maribavir has been mapped to UL97 mutations at codons 353, 397, 409 and 411, in the kinase ATP-binding region, and to mutations in the UL27 gene. We studied the maribavir susceptibility phenotypes of additional UL97 mutations observed in vitro and in clinical trials, and the effect of simultaneous mutation in both UL97 and UL27. In vitro selection under maribavir identified a new locus of UL97 mutation within the conserved kinase p-loop (L337M), which conferred low grade maribavir resistance (3.5-fold increased EC50) without ganciclovir cross-resistance. During maribavir Phase III CMV prevention clinical trials, three previously unknown UL97 sequence variants were detected in plasma samples after 27-98 days of drug exposure (I324V, S334G and S386L). These variants did not confer any drug resistance despite proximity to mutations that confer maribavir resistance. The UL27 resistance mutation R233S, when added to strains containing UL97 mutations L337M or V353A, doubled their maribavir EC50s. These results expand the range of UL97 maribavir-resistance mutations into another part of the kinase ATP-binding region, but offer no genotypic evidence that development of drug resistance affected the outcomes of Phase III maribavir clinical trials after drug exposure of up to 14 weeks. There is a potential for increased maribavir resistance in UL27-UL97 double mutants.
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Affiliation(s)
- Sunwen Chou
- Division of Infectious Diseases, Oregon Health and Science University, Portland, OR 97239, USA.
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Cai X, Han S, Chou S. Small but Consequential: A Case of Deep Intracerebral Hemorrhage (ICH) Caused by Distal Lenticulostriate Artery Aneurysm (P05.218). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.p05.218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Hakki M, Drummond C, Houser B, Marousek G, Chou S. Resistance to maribavir is associated with the exclusion of pUL27 from nucleoli during human cytomegalovirus infection. Antiviral Res 2011; 92:313-8. [PMID: 21906628 DOI: 10.1016/j.antiviral.2011.08.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 08/18/2011] [Accepted: 08/22/2011] [Indexed: 01/13/2023]
Abstract
Select mutations in the human cytomegalovirus (HCMV) gene UL27 confer low-grade resistance to the HCMV UL97 kinase inhibitor maribavir (MBV). It has been reported that the 608-amino acid UL27 gene product (pUL27) normally localizes to cell nuclei and nucleoli, whereas its truncation at codon 415, as found in a MBV-resistant mutant, results in cytoplasmic localization. We now show that in the context of full-length pUL27, diverse single amino acid substitutions associated with MBV resistance result in loss of its nucleolar localization when visualized after transient transfection, whereas substitutions representing normal interstrain polymorphism had no such effect. The same differences in localization were observed during a complete infection cycle with recombinant HCMV strains over-expressing full-length fluorescent pUL27 variants. Nested UL27 C-terminal truncation expression plasmids showed that amino acids 596-599 were required for the nucleolar localization of pUL27. These results indicate that the loss of a nucleolar function of pUL27 may contribute to MBV resistance, and that the nucleolar localization of pUL27 during HCMV infection depends not only on a carboxy-terminal domain but also on a property of pUL27 that is affected by MBV-resistant mutations, such as an interaction with component(s) of the nucleolus.
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Affiliation(s)
- Morgan Hakki
- Division of Infectious Diseases, Oregon Health & Science University, Portland, OR 97239, USA.
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Chou S, Marousek G, Auerochs S, Stamminger T, Milbradt J, Marschall M. The unique antiviral activity of artesunate is broadly effective against human cytomegaloviruses including therapy-resistant mutants. Antiviral Res 2011; 92:364-8. [PMID: 21843554 DOI: 10.1016/j.antiviral.2011.07.018] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2011] [Revised: 07/13/2011] [Accepted: 07/21/2011] [Indexed: 12/26/2022]
Abstract
Current therapy options to treat infections with human cytomegalovirus face severe limitations leading to a continued search for novel drug candidates. Here, we describe novel characteristics of the strong antiviral potency of the drug artesunate. In vitro virus replication systems were applied to analyze a number of laboratory and clinically relevant strains of human cytomegalovirus. An inhibitory block at a very early stage of infection was demonstrated. Time-of-addition experiments indicated that the antiviral efficacy could be optimized when artesunate was applied as fractional doses consecutively added post-infection. Artesunate showed a clearly higher anti-cytomegaloviral activity than its parental drug artemisinin (approximately 10-fold) or other artesunate-related compounds. Mean IC(50) values of artesunate for a variety of standard therapy-resistant virus mutants were within a 2-fold range compared to wild-type virus. Furthermore, a synergistic effect was identified when artesunate was combined with the mechanistically distinct antiviral compound maribavir. These findings point to unique antiviral properties of artesunate which may offer an advantage over standard antiviral therapy particularly in cases of drug resistance.
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Affiliation(s)
- Sunwen Chou
- Division of Infectious Diseases, Oregon Health and Science University, Portland, Oregon, USA
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Wolf DG, Shimoni A, Resnick IB, Stamminger T, Neumann AU, Chou S, Efferth T, Caplan O, Rose J, Nagler A, Marschall M. Human cytomegalovirus kinetics following institution of artesunate after hematopoietic stem cell transplantation. Antiviral Res 2011; 90:183-6. [PMID: 21443904 DOI: 10.1016/j.antiviral.2011.03.184] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 03/21/2011] [Indexed: 10/18/2022]
Abstract
The anti-malaria drug artesunate has been shown to be an effective inhibitor of cytomegalovirus (CMV) in vitro, in an experimental animal model, and in a recent single-case clinical use. In this first case-series of 6 stem cell transplant recipients who received preemptive artesunate treatment for CMV infection, we have examined the viral kinetics following institution of artesunate, and employed first-phase viral kinetics studies to calculate its antiviral effectiveness. Two patients demonstrated a rapid 0.8-2.1 log viral load decline by 7 days, with a viral decay half-live of 0.9-1.9 days. Four patients demonstrated a continued yet stalled viral growth slope during treatment. No adverse events were noted in treatment courses of up to 28 days. Overall, a divergent antiviral efficacy was revealed, ranging from 43% to 90%, which appeared to be primarily dependent on the virus baseline growth dynamics. Further dose escalation studies are needed to examine the role of artesunate in the treatment of CMV infection in the transplantation setting.
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Affiliation(s)
- Dana G Wolf
- Clinical Virology Unit, Hadassah Hebrew University Medical Center, Jerusalem, Israel.
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Avery RK, Marty FM, Strasfeld L, Lee I, Arrieta A, Chou S, Tatarowicz W, Villano S. Oral maribavir for treatment of refractory or resistant cytomegalovirus infections in transplant recipients. Transpl Infect Dis 2011; 12:489-96. [PMID: 20682012 DOI: 10.1111/j.1399-3062.2010.00550.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Despite advances in cytomegalovirus (CMV) prophylaxis and therapy, some transplant recipients still develop refractory CMV infections. Maribavir (MBV), an investigational benzimidazole antiviral agent, acts by a mechanism different from that of existing anti-CMV drugs. Previous Phase I and II studies have demonstrated a favorable safety profile for MBV, but its utility in treatment of complex CMV syndromes is unknown. METHODS Between June and December 2008, MBV was released for use under individual emergency investigational new drug applications requested by treating physicians and approved by the US Food and Drug Administration and local institutional review boards. Six patients (5 solid organ transplant recipients and 1 hematopoietic stem cell transplant recipient) who had failed to respond to other therapies and/or had known ganciclovir-resistant CMV were treated with MBV at a starting oral dose of 400 mg twice daily. RESULTS Patients were treated for a median of 207 days (range, 15-376). Four of 6 patients had no detectable CMV DNAemia within 6 weeks of starting MBV therapy. One patient, who had an initial viral load of 1.8 million copies/mL, developed MBV resistance mutations. One patient, who had low serum levels of MBV, had persistent CMV DNAemia and viruria without developing genotypic or phenotypic resistance to MBV. One patient cleared CMV DNAemia, but died of pneumonia and multiorgan failure. No significant adverse effects attributable to MBV were observed. CONCLUSIONS MBV deserves further systematic evaluation as treatment for CMV infection that is resistant and/or refractory to standard therapies, but its optimal dose, duration of therapy, and use in combinations versus as a single agent have yet to be determined.
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Affiliation(s)
- R K Avery
- Infectious Diseases, The Cleveland Clinic, Cleveland, Ohio, USA
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Chou S. Phenotypic diversity of cytomegalovirus DNA polymerase gene variants observed after antiviral therapy. J Clin Virol 2011; 50:287-91. [PMID: 21295516 DOI: 10.1016/j.jcv.2011.01.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 12/20/2010] [Accepted: 01/06/2011] [Indexed: 01/01/2023]
Abstract
BACKGROUND Cytomegalovirus UL54 DNA polymerase mutations observed in clinical specimens are of diagnostic significance if confirmed to affect antiviral drug susceptibility. OBJECTIVES Validate an updated recombinant phenotyping method to determine the degree of drug resistance conferred by previously uncharacterized UL54 sequence variants, in comparison with known resistance-related mutations. STUDY DESIGN Bacterial artificial chromosome clones of viral DNA were mutagenized by recombination, transfected to produce live virus and phenotyped by standardized reporter-based yield reduction assays. RESULTS Sixteen recombinant viruses were constructed, representing baseline sequences, known resistance-related mutations and amino acid changes of unproven significance from clinical specimens. Phenotypes of baseline strains and known mutants were comparable to results from prior methods and helped to resolve some published inconsistencies. Mutations F412L, F412S, L545W were newly confirmed to confer ganciclovir and cidofovir resistance, while Q578H conferred ganciclovir and foscarnet resistance with borderline cidofovir resistance. Some foscarnet-resistant mutants were appreciably growth-retarded. CONCLUSIONS Results add to known exonuclease domain mutations that confer ganciclovir-cidofovir cross-resistance, polymerase domain mutations that confer foscarnet resistance with variably decreased ganciclovir/cidofovir susceptibility, and increase the list of sequence variants with no measurable impact on drug susceptibility. The phenotypic diversity of similar UL54 genotypic variants complicates the interpretation of genotypic resistance testing. Technical improvements are facilitating the phenotyping of remaining unknown sequence variants.
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Affiliation(s)
- Sunwen Chou
- Division of Infectious Diseases, Oregon Health and Science University and Department of Veterans Affairs Medical Center, Portland, OR 97239, USA.
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Chou S, Cai X, Konigsberg R, Bresette L, Henderson G, Sorond F, Ropper A, Feske S. Thromboembolic risks of recombinant factor VIIa use in warfarin-associated intracranial hemorrhage. Crit Care 2011. [PMCID: PMC3068362 DOI: 10.1186/cc9853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Abstract
Antiviral drug resistance is an increasing concern in immunocompromised patient populations, where ongoing viral replication and prolonged drug exposure lead to the selection of resistant strains. Rapid diagnosis of resistance can be made by associating characteristic viral mutations with resistance to various drugs as determined by phenotypic assays. Management of drug resistance includes optimization of host factors and drug delivery, selection of alternative therapies based on knowledge of mechanisms of resistance, and the development of new antivirals. This article discusses drug resistance in herpesviruses and hepatitis B.
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Affiliation(s)
- Lynne Strasfeld
- Division of Infectious Diseases, Oregon Health & Science University, Portland, OR 97239, USA.
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Abstract
Antiviral drug resistance is an increasing concern in immunocompromised patient populations, where ongoing viral replication and prolonged drug exposure lead to the selection of resistant strains. Rapid diagnosis of resistance can be made by associating characteristic viral mutations with resistance to various drugs as determined by phenotypic assays. Management of drug resistance includes optimization of host factors and drug delivery, selection of alternative therapies based on knowledge of mechanisms of resistance, and the development of new antivirals. This article discusses drug resistance in herpesviruses and hepatitis B.
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Affiliation(s)
- Lynne Strasfeld
- Division of Infectious Diseases, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, mail code L457, Portland, OR 97239, USA.
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Strasfeld L, Lee I, Tatarowicz W, Villano S, Chou S. Virologic Characterization of Multidrug‐Resistant Cytomegalovirus Infection in 2 Transplant Recipients Treated with Maribavir. J Infect Dis 2010; 202:104-8. [DOI: 10.1086/653122] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Elyas R, Guerra LA, Pike J, DeCarli C, Betolli M, Bass J, Chou S, Sweeney B, Rubin S, Barrowman N, Moher D, Leonard M. Is staging beneficial for Fowler-Stephens orchiopexy? A systematic review. J Urol 2010; 183:2012-8. [PMID: 20303527 DOI: 10.1016/j.juro.2010.01.035] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Indexed: 10/19/2022]
Abstract
PURPOSE Fowler and Stephens showed that by dividing the spermatic vessels a high intra-abdominal testis could be placed in the scrotum. Testicular atrophy is a potential complication of this technique. We conducted a systematic review to determine whether single or 2-stage Fowler-Stephens orchiopexy results in better testicular viability. MATERIALS AND METHODS We searched electronic databases, clinical trial registries and gray literature. We included reports describing boys younger than 18 years with a primary outcome of "testicular viability and position." We performed a meta-analysis using random effects models. Heterogeneity was assessed using forest plot and I(2) statistic. RESULTS We identified 1,807 citations and included 61 articles. Single stage Fowler-Stephens orchiopexy was discussed in 9 articles, a 2-stage procedure in 36 and both approaches in 16. There were no randomized controlled trials, and most studies were cohort or case series. The pooled estimate of success rates was 80% for single stage Fowler-Stephens orchiopexy (95% CI 75 to 86) and 85% for 2-stage Fowler-Stephens orchiopexy (95% CI 81 to 90). The pooled odds ratio of single stage vs 2-stage Fowler-Stephens orchiopexy was 2.0 (95% CI 1.1 to 3.9) favoring the 2-stage procedure. There was no difference in the success rate between laparoscopic and open techniques in either single or 2-stage Fowler-Stephens orchiopexy. There was no evidence of asymmetry on the funnel plot. There were no complications reported with single stage, while ileus, hematoma and infection were the most common complications with 2-stage Fowler-Stephens orchiopexy. CONCLUSIONS Both techniques have a fairly high success rate but 2-stage Fowler-Stephens orchiopexy appears to carry a higher rate of success than the single stage approach (85% vs 80%, OR 2 in favor of 2-stage). Laparoscopic and open techniques had the same success rate. However, the level of evidence of the studies was low, and a study of a more robust design, such as a randomized controlled trial, should be performed.
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Affiliation(s)
- R Elyas
- Queens University, Kingston, Ontario, Canada
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Iwasenko JM, Scott GM, Rawlinson WD, Keogh A, Mitchell D, Chou S. Successful valganciclovir treatment of post-transplant cytomegalovirus infection in the presence of UL97 mutation N597D. J Med Virol 2009; 81:507-10. [PMID: 19152402 PMCID: PMC2786239 DOI: 10.1002/jmv.21397] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Mutations in the human cytomegalovirus (CMV) UL97 protein kinase are the most common mechanism of ganciclovir (GCV) resistance in the clinical setting. A CMV strain with a previously unrecognized UL97 mutation N597D was identified in the blood of a heart transplant recipient who experienced a persistent CMV infection with high viral loads accompanying pain and fever while receiving valganciclovir (valGCV) therapy. The N597D mutation was transferred by mutagenesis to an antiviral sensitive CMV strain for analysis of antiviral susceptibility by standardized phenotypic assay. Recombinant phenotyping showed N597D conferred a less than twofold increase in GCV IC(50) compared to the sensitive control strain. Despite the presence of this mutation, valGCV eventually resolved the infection after 6 weeks of therapy. A subsequent CMV reactivation was also responsive to valganciclovir. This case illustrates the diversity of UL97 mutations in the codon segment 590-607 usually associated with GCV resistance, with some mutations producing minimal levels of resistance that do not preclude a therapeutic response to the drug. Accurate interpretation of genotypic test results ultimately requires experimental determination of the level of resistance conferred by newly discovered UL97 mutations.
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Affiliation(s)
- Jenna M Iwasenko
- Virology Division, Department of Microbiology, SEALS, POWH & UNSW Research Laboratories, Prince of Wales Hospital, Randwick, NSW, Australia
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Gill RB, Frederick SL, Hartline CB, Chou S, Prichard MN. Conserved retinoblastoma protein-binding motif in human cytomegalovirus UL97 kinase minimally impacts viral replication but affects susceptibility to maribavir. Virol J 2009; 6:9. [PMID: 19159461 PMCID: PMC2636770 DOI: 10.1186/1743-422x-6-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Accepted: 01/21/2009] [Indexed: 11/10/2022] Open
Abstract
The UL97 kinase has been shown to phosphorylate and inactivate the retinoblastoma protein (Rb) and has three consensus Rb-binding motifs that might contribute to this activity. Recombinant viruses containing mutations in the Rb-binding motifs generally replicated well in human foreskin fibroblasts with only a slight delay in replication kinetics. Their susceptibility to the specific UL97 kinase inhibitor, maribavir, was also examined. Mutation of the amino terminal motif, which is involved in the inactivation of Rb, also renders the virus hypersensitive to the drug and suggests that the motif may play a role in its mechanism of action.
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Affiliation(s)
- Rachel B Gill
- Department of Pediatrics, University of Alabama School of Medicine, Birmingham, AL, USA.
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